Information terminals, such as a mobile phone and a personal computer (PC), which communicate in a wireless wide area network (hereinafter referred to as “wireless WAN”), e.g., mobile telephone network, have subscriber identity module (hereinafter, referred to as “SIM”) cards mounted thereto.
Such SIM cards are storage supplied by wireless WAN communication operators, and are used while being mounted on information terminals, e.g., mobile phones. A SIM card has information about a subscriber of a communication operator, stored therein. A unique number, known as an international mobile subscriber identity (IMSI, hereinafter referred to as “SIM information”), is assigned to a single SIM card, and the IMSI is related to a telephone number. When a SIM card is inserted into a SIM card slot in an information terminal, the information terminal can perform voice calls and data communications and use services provided by the communication operator. Conversely speaking, unless a user possesses a SIM card and inserts it into an electronic device, the user is not able to perform voice calls and data communications or use the services provided by the communication operator, on that electronic device.
By detaching and inserting a SIM card from and to information terminals, a telephone number can be migrated between information terminals. Further, by using multiple SIM cards, multiple telephone numbers can be used on a single information terminal.
A single telephone number is related to a SIM card, a basic fee for an information terminal and charges for voice calls and data communication service are charged for each SIM card.
Patent Reference 1: Japanese National Publication of International Patent Application No. 2001-505372
In conventional information terminals, for using a single SIM card on multiple information terminals, the SIM card is required to be detached from one information terminal and then inserted to another information terminal.
A single piece of SIM information is related to a single SIM card. Hence, once a SIM card is inserted to an information terminal, that SIM card cannot be used in another information terminal. Accordingly, for using one SIM card on multiple information terminals, detachment and insertion of that SIM card is required. The procedure for switching a connection between information terminals is quite cumbersome.
Since time delay is caused by a reconnection during switching between information terminals, a seamless provision of services is not possible.
Since each information terminal has its own SIM card, respective communication services are provided on these information terminals. Hence, in some cases, a basic fee is charged for each information terminal (i.e., for each SIM card).